How to increase width of the row?

Ho can we increase the width of the row? (e.g) created Field in Purchase order Shipment: ( by sea 1 x 20ft container ) this comes in 2 rows want to make the row length wide

Are you referring to a child table and/or List view column width?

If so, this is a field you can customize. These fields are at the bottom of the Customize Form Field editor.